A senior US general is believed to be under investigation for allegedly
leaking details of a secret cyberattack on Iran.

James Cartwright, who was the US military's second-highest-ranking officer before retiring in 2011, is said to be the target of an inquiry by the US justice department into how the media obtained information on the Stuxnet strike on Iranian nuclear facilities.

The computer virus, which is believed to have been unleashed by US and Israeli engineers in 2010, temporarily disabled 1,000 centrifuges within Iran’s nuclear programme.

The New York Times last year published a detailed account, sourced to anonymous officials, of how the virus was developed.

It was reported to have been part of a wider cyber-attack codenamed Olympic Games, which began under former president George W Bush and was extended under President Barack Obama.

Gen. Cartwright, 63, was credited in the front-page article with overseeing the operation. He has now received a letter from justice department officials informing him that he is the subject of the leak inquiry, according to NBC News.

The 63-year-old is the highest-profile official so far to be targeted by an aggressive crackdown on leakers by Mr Obama’s administration, which has prosecuted more people under the espionage act than all past administrations combined.

Inquiries into two other leaks have seen phone records seized for reporters from the Associated Press and emails obtained from a journalist for Fox News, prompting fierce criticism of the administration from American media organisations.

The disclosures in The New York Times’s article were excerpted from a book by David Sanger, one of its correspondents, titled Confront and Conceal.

The book also contained several other inside accounts of the administration’s national security operations.

Sanger wrote that his reports were “based on interviews over the past 18 months with current and former American, European and Israeli officials involved in the programme”, adding: “None would allow their names to be used because the effort remains highly classified”.

Its leak prompted furious accusations from Republicans that Mr Obama’s aides had deliberately released information to the media in order to bolster his credentials as commander-in-chief and improve his chances of securing re-election in last November’s presidential poll.

Gen Cartwright, a 40-year veteran of the Marines, served as deputy chairman of the joint chiefs of staff between 2007 and 2011.

He was at one stage one of Mr Obama’s most trusted advisers and was once viewed as the likely front-runner for promotion to chairman of the joint chiefs of staff - America’s most senior officer.

However he is said to have fallen foul of colleagues by discreetly siding with Joe Biden, the Vice-President, during Mr Obama’s 2010 review of the war in Afghanistan. While other top generals, such as David Petraeus, then commander of US forces in the conflict, wanted a boost in US troop numbers, Mr Biden urged the president to hasten America’s withdrawal.

The chairmanship eventually went to Gen Martin Dempsey, the former chief of staff of the Army. Gen Cartwright now serves as a chair in defence policy studies at the Center for Strategic and International Studies, a Washington think-tank.

If indicted and convicted under the espionage act, Gen Cartwright could face a lengthy prison sentence. Gen Cartwright could not be reached for comment. His attorney told NBC News: “I have no comment”.